package ckprompt

import (
	commandkit "go.maximumdirect.net/commandkit"
	promptkit "go.maximumdirect.net/promptkit"
)

// WithNamespaces enables standard resource namespace selection with explicit
// defaults. Supplied CLI namespace flags replace only the corresponding default.
// Loaders used with this option should leave namespace selection to the adapter.
func WithNamespaces[I, S any](suite Suite[I, S], defaults promptkit.Namespaces) Suite[I, S] {
	suite.namespaces = &defaults
	return suite
}

type namespaceInput struct {
	prompt, profile, backend commandkit.Supplied[string]
}

func namespaceFlags[I any](destination func(*I) *namespaceInput, kinds ...string) []commandkit.Flag[I] {
	flags := make([]commandkit.Flag[I], 0, len(kinds))
	for _, kind := range kinds {
		var meta commandkit.FlagMeta
		var field func(*namespaceInput) *commandkit.Supplied[string]
		switch kind {
		case "prompt":
			meta = namespaceFlagDefinitions.prompt.meta
			field = func(input *namespaceInput) *commandkit.Supplied[string] { return &input.prompt }
		case "profile":
			meta = namespaceFlagDefinitions.profile.meta
			field = func(input *namespaceInput) *commandkit.Supplied[string] { return &input.profile }
		case "backend":
			meta = namespaceFlagDefinitions.backend.meta
			field = func(input *namespaceInput) *commandkit.Supplied[string] { return &input.backend }
		}
		flags = append(flags, commandkit.ValueFlag(meta, (*string)(nil), parseDefinitionString, func(input *I, value commandkit.Supplied[string]) { *field(destination(input)) = value }))
	}
	return flags
}

var namespaceFlagDefinitions = struct{ prompt, profile, backend requestFlagDefinition }{
	prompt:  requestFlagDefinition{commandkit.FlagMeta{Name: "llm-prompt-namespace", Usage: "Prompt resource namespace."}, []string{"prompt-namespace"}},
	profile: requestFlagDefinition{commandkit.FlagMeta{Name: "llm-profile-namespace", Usage: "Profile resource namespace."}, []string{"profile-namespace"}},
	backend: requestFlagDefinition{commandkit.FlagMeta{Name: "llm-backend-namespace", Usage: "Backend resource namespace."}, []string{"backend-namespace"}},
}

func selectedNamespaces(defaults *promptkit.Namespaces, selected namespaceInput) *promptkit.Namespaces {
	if defaults == nil {
		return nil
	}
	value := *defaults
	if selected.prompt.Set {
		value.Prompt = selected.prompt.Value
	}
	if selected.profile.Set {
		value.Profile = selected.profile.Value
	}
	if selected.backend.Set {
		value.Backend = selected.backend.Value
	}
	return &value
}

func namespacedEngine(engine *promptkit.Engine, namespaces *promptkit.Namespaces) (*promptkit.Engine, error) {
	if namespaces == nil {
		return engine, nil
	}
	return engine.WithNamespaces(*namespaces)
}